Re: Robert Dewar's great article about the Strengths of Ada over other langauges in multiprocessing!

[george.priv@gmail.com]

On Mar 9, 8:40 am, Vadim Godunko <vgodu...@gmail.com> wrote:
> On Mar 9, 11:20 am, Pascal Obry <pas...@obry.net> wrote:
>
> > I prefer using Ada, even losing 10% performance initially.
>
> I usually have 4+ times penalty for Ada program with controlled object
> for memory allocation/deallocation control and protected objects for
> thread safe operations in comparison with equivalent C++ program. :-(
>
> #include <QString>
> #include <QTime>
>
> void test(unsigned length)
> {
>         uint x[length];
>         QString a[1024];
>         QString b[1024];
>         QTime timer;
>
>         timer.start();
>
>         for (int i = 0; i < 1024; i++)
>         {
>                 a[i] = QString::fromUcs4(x, length);
>         }
>
>         qDebug("Init %d %lf", length, (double)timer.elapsed() / 1000);
>
>         timer.restart();
>
>         for (int i = 0; i < 1000; i++)
>         {
>                 if (i % 2)
>                 {
>                         for (int j = 0; j < 1024; j++)
>                         {
>                                 a[j] = b[j];
>                         }
>                 }
>                 else
>                 {
>                         for (int j = 0; j < 1024; j++)
>                         {
>                                 b[j] = a[j];
>                         }
>                 }
>         }
>
>         qDebug("Copy %d %lf", length, (double)timer.elapsed() / 1000);
>
> }
>
> int main()
> {
>         test (128);
>         test (1024);
>         return 0;
>
> }
>
> with Ada.Calendar;
> with Ada.Wide_Wide_Text_IO;
>
> with League.Strings;
>
> procedure Speed_Test_League is
>
>    type Universal_String_Array is
>      array (Positive range <>) of League.Strings.Universal_String;
>
>    procedure Test (Length : in Positive);
>
>    procedure Test (Length : in Positive) is
>       use type Ada.Calendar.Time;
>
>       X : constant Wide_Wide_String (1 .. Length) := (others => ' ');
>       A : Universal_String_Array (1 .. 1_024);
>       B : Universal_String_Array (1 .. 1_024);
>       S : Ada.Calendar.Time;
>
>    begin
>       S := Ada.Calendar.Clock;
>
>       for J in A'Range loop
>          A (J) := League.Strings.To_Universal_String (X);
>       end loop;
>
>       Ada.Wide_Wide_Text_IO.Put_Line
>        ("Init"
>           & Positive'Wide_Wide_Image (Length)
>           & Duration'Wide_Wide_Image (Ada.Calendar.Clock - S));
>
>       S := Ada.Calendar.Clock;
>
>       for J in 1 .. 1_000 loop
>          if J mod 2 = 1 then
>             B := A;
>
>          else
>             A := B;
>          end if;
>       end loop;
>
>       Ada.Wide_Wide_Text_IO.Put_Line
>        ("Copy"
>           & Positive'Wide_Wide_Image (Length)
>           & Duration'Wide_Wide_Image (Ada.Calendar.Clock - S));
>    end Test;
>
> begin
>    Test (128);
>    Test (1_024);
> end Speed_Test_League;

This code is not multi-core safe.  Are you sure that QString has
Vtab?  If not then comparison will be unfair.